Telephone system



G. DEAKlN TELEPHONE SYSTEM Filed April 30, 1927 Oct. 29, 1929.

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G ERALDDEAXIN', or ANTWERP, BELGIUM, AssIGNOn Tol WEsTERNELEOTnIc COM- PANY, INcORPOnATED, OF NEW YORK, N. Y., n OoRrOnA'IION or NEW YORK 1 f TELEPHONE SYSTEM Application med April ao, 1927, serial No.

This invention relates to telephone systems and has for its object the provisionoffimproved means for extending telephonicconnections between manual and machineswitching offices. d

One arrangement for the establishment of such connections, which has heretofore been proposed, used a three-way link circuit at kthe manual oiice, thaty is, a link circuit which was provided with` three switches one of which associated the 'link withequipmentlocated at the operators position, a v,second which associated the link ywith an idle sender and a third which associated the link with an idle trunk to the machine switching oIice. In this arrangement, the link became a part of the connection when completed. A modification of this y arrangement employed a link which was provided with switches performing the above` mentioned functions ybut which, in' addition, gave an indication to the operator of theselected trunk whereupon the connection was established independent of the link, which reverted to common use. d

In accordance with the ypresent invention, link circuits yfor associating an idle sender with an idle trunkand the'equipment at the operators position arek eliminated, thereby reducing the ,amount of apparatus required.

The extension "of a calling `line to a set of terminals individual to; the `wanted 1 office causes the association of a senderwith an idle trunk outgoing to'tllatoiice, after which the trunk is associated withthe terminals. When the connection has been established the sender u is released,` In addition, ,thev sender is `provided with means to testV both the incoming l and outgoing ends of theoilice trunk ybefore appropriating it for use. d e d' d j, The preferred embodiment ofthe present invention, specilically statedcomprises jacks at the manual oilce allotted to the automatic olices to which the manual voiiice has access, these jacks being connected to the banks of selector switches in which the interoilice trunks terminate. Theoperators at the manual oflice have access'to these jacks by fmeans of cord circnitsof the usual character. There area number of senders common to all of the jacks, each of which is lprovided with a selec- 187,968; and in Italy November so, 192e.

tor` switch whichhas access to the interoice trunks. o The `insertion of a plugin a jack completes a start circuit for the trunk selectors k,of all idle senders. kWhen a sender has rfound a trunk ywhich is idle at its incoming end, it comes to rest and stopsthe trunk hunting operation of the remaining senders.` It

then tests the outgoing end of the trunk and, if that is also jidle, establishes the' necessary control circuits. As soon as atrunk has been selected, the jack selector of the trunk is operated to find the yjack into which the operator yhas inserted her plug, y As soon as the jack has f been found, a keyset at the Operators position f is connected tothe registers of the sender and the wanted number recorded. The sender then functions to ,control the extension yof the connection over the switches of the auto-k matic ollice, after which the talking conductors are connectedthrough to the'fjack, `the operators key set is disconnected, and the sender is released to revert to common use.

rThe scope and purpose of the invention will v ly set forth the invention; and

ybe more clearlyunderstood froma considera-y Fig.y 2 is a'skeleton diagram of the connecf tion established by theapparatus of Fig'1.

o j ,Assuming that the subscribery at substation ,100, located in a manual oilice, wishes to converse with'the subscriber atsubstati'on 150, located in a machine switchingfoliice, he will remove his receiver from the switchhook, s1g- .usual manner. Theoperator will insert the answering plugof cord circuit 102 in the line jack and receivey :from the wanted subscriber n the number of the wanted subscriberrs line.

"naling the operatorin the central otlice in the d She will then insert the calling plug yof ythe 105, to'ground. A branch'ofthi's circuit eX- tends` to terminal 107 in thebank of vjack inder 110 lmarking the jack to which the call has been extended in the nder bank. Relay 104 operates, connecting the operators key set to terminals 108 and 109 in the inder bank. It also closes a circuit from battery over its lower contact through resistances 111 and 112, winding of relay 113, resistance 160, to grouifid. A branch of this circuit extends from a point between resistances 111 and 112 to terminal 106 in the jack finder bank. Relay 113operates, closing anobyious circuit for starting relay 114. Relay 114C 1n operating closes start circuits to all senders; In the case ot' those senders which are not in use with some other call, the start vcircuit is `=coinpleted. For the sender shown, this may be traced ifroin battery ovei'1 the uppermost contact of 'relay 114, lower contact foi jacl: 115, back Contact of relay 116, winding of power magnet 117 of trunk lnder 126, back contact ot' relay 118, conductor 130, lower lei:`t contaet of cam 119 of the sequence switch which controls the oper-'ation of the sender, to lground through other apparatus of the slender, not shown.` Magnet 117 'is energized 1n this circuit, 'causing the brushes 'of the trunk finder to move Yover the terminals of the 'trunks appearing beoreit. Relay 114 closes a circuit from battery through its inner lower Contact to vall idle trunk circuits of the group. In the 'case of the trunk shown, the circuit may be traced from contact of relay 114, resi-stance 161, lower back Contact of relay 134, to terminal 122. Assuming that the trunk shown is the lirst idle trunk encountered by the trunk finder 120, this circuit will be vextended over vthe bruslfi of the trunk linder, upper Contact of jack 115, left high resistance windingfoi relay 118, to ground. Relay 118 operates,

closing a circuit from battery through the winding of relay 129, liront Contact of relay 118,?co`n'ductor 130, to ground, 'over the lower left contact of cam 119. Relay 129 operates, connecting yground `over its outer left front `contact to the right low resistance winding of lay 118. rEhi-s reduces the potential of terin el 122 te' render the trunk circuit busy to other senders. Y

4.heuld wo trunkiin'ders, such as 120, simultane'ouslyk test the same trunk, the relays corresponding to relay 118 of eachy findercircuit would operate, Vin turn causing the opera'- tion of relays such as 129. The adjustment of relays 118 is such however, that two Y'of them will not remain energized with their low resistance windings Vin multiple. Therelfore both will release and hunting Vwill contin-ee'. y 4

The operation oi relay '118 vopens the above Itraced circuit -t'or power magnet 117 and brings the brushes of finder 120 to rest. A test is no'wfmade of the outgoing end of the trunk. II" the machine switching apparatus in 'weich ther trunk terminates atv the mechanical oiice condition to extend the vconnection, the sequence' switch associated there;

with will be standing in position 1 and ground will be connected to cam 132 over its lower contact. A circuit will therefore be closed as soon as the brushes 01": switch 120 come te rest, from battery through the winda ing of Arelay 131, inner left front contact of rel-ay 129, brush oil trunk finder 120 resting on terminal 125, upper back contact of relay 133, upper back Contact oferelay 134e, over the tip conductor oi the v interotlice trunk 162, lower contact of cam 132, to ground. Relay 131 in i operating' prevents the linder from advancing further by opening a second energizing circuit or' magnet u117 whichotherwise would extend from magnet 117, over the left bach 'Contact 'of 'relay 131, right front contact of relay 129, to grounded conductor 130.

It ground were not connected to the tip conductor, relay 131 would not operate and the switch would advance again. As theli- Aswitch leaves the terminals of the trunk, relay 118 releases, lturn releasing relay 129 and 'restoringA the irst energizing circuit of magnet 11T. It therefore tests the incoming and outgoing e'ndsof the next tru'n'lr in succes! sion, as described for the first trunk.

VAssnmin-g that the trunl'r first tested is also tree at the distant end, the operation of relay 131 `closes fan' energizing' 'circuit for power magnet 135,*i'vhif'ch controls the jack finderLA 110. This circuit may be traced from battery through the win ding oit magnet 135,'ter1ninal 12? and brush of trliinh linde'r 120, back contactof relay 136, left front contact 'of relay 131, right front' 'contact of relay 129, to grounded 'conductor 130.. Switch 110 is rotated until Contact is made with terminal 106, to which battery was connected through resistance 111. lit-'this time a circuit is closed from battery on terminal 106 over the brush of the `jack finderV 11,0, inner lower Contact of jack 137, terminal 126, 'left high resistance winding of rrelay 136, toV ground at the right front contact 'ofrelay 131. Relay 1f36operaltes, opening thewcirc'uit kof power magnet w135, bringingthe jack finder to rest on the terminals individual to jack 1033. It also closesV Va ,circuit fromY battery through the 'windingfoif relay 116, iront Contact of relay 136,5 left :front Contact 'of relay 131, right 11"6fcloses Aan 'obviousV Contact forrelay 138.

At left Contact relay 116 'disconnectsbattery'frointhe energizing circuit lof magnet 117. The 'connection ef ground through a l'ow to g'roun'da'tthe outerri'ght contact i resistance toterminal 106 shunts the ywinding of relay 113, and that relay releases,-in turn releasing relay 114 and removing 'battery from the sender start circuit-s and from the trunktest circuits.` `The release of relay 114 also opens the circuit orelay 118 which releases in turn releasing relay 129. With relay 129 released, groundis `connected over its outer left back contact and/'the inner right front.contact'offrelay138 to maintain the busy condition onfterminal 122. i

Relay 138,` in operating, closes a circuit from battery through the winding of relay 133, terminal 123, and the corresponding brush, middle right contact of relay 138, to ground at the upper right cont-act of cam 119. Relay 133, in operating, connects jthe operators key set through to the 'registers of thesender, the circuit being traceable from the key set'over the outer upper front contact of relay 104, terminal 109, upperfront contact of relay 133, terminal 125, innerbaclr contact of relay 129, outer left contact of relay 138, upper contact of cam 139to the registers, back over the left contact of cam 140, middle left contact of relay 138, `terminal 124,'inne'r lower front contact of relay '133, terminal` 108,y inner yupper-front contact of relay 104, tothe key set- 'The registers will [nowfbe set from thelkey set in any suitable manner, foreXampleas shownin the patent to Gerald Deakin, 1,653,890, granted 1360.2?,1921 f .Y y

Relay 133 in operating also closesfa circuit from ground over its `outer'lower front contact, windings of yrelay 141` in series, upper contact ofvjaclr137, terminal 107 to battery over the sleeves of jack 103 andthe cord plug. Relay 141 closes an obvious circuit for busy lamp 142. It also closes afcircuit from ground at its outer right front contact, resistance 144, and thence in parallel through the winding of relay 134 tobattery andover terminal 121, outer right contact of relay138, and winding` of] relay 145 to battery.;` Relay 145 operates to 'hold certain s enderfcircuits open, but relay 134'cannot operate in parallel with relay 145. At its left contactrelay 141 closes aj link in an all-:trunksbusyy chain circuit.

Atits inner fright rfront ycontact it `prepares afeircuitrthro'ugh its low resistance winding yalone.

VVhenfy the registers have been completely fpositionedythe sendersequence'switch is ad` 'vanced' to "position 3.' f At this time, the'circuit of relay k133is'fo'pened, 'and thatrelay releases', permitting'theclosure of acircuit from battery inl the Vcord rcireli'it a102, sleeves of the cord plug andiack '103,brush 107,111)- per contact offjack 137 low resistance winding! and inner' right'contact or relay 141, to ground at the backjcon'taet of relay 133.

The release of relay `133extendsfthemtip and ringconductors of the interoiic'e trunk through to' the selection control apparatus.

Fig. 1.

These circuits may be traced in part from bat- 129, outer lefticontact of relay 138, lower Contact of cam 139, winding offstepping relay 148, resistance 149, to the selection control apparatus.. Relays 148 and 146 operate in this lfundamental circuit, relay 146 initiating the opera-tion of the selector 151. The commutator represented` schematically at'153 is moved with the selector switch, holding relay 146 op` e erated 'and shunting relay 148 to cause theoperation of the counting relays in the well known manner. Switch 151 is operated to select anidle tinaliselector switch 152 which is then operated to select the called subscribers line 150. i e

When relay 133 'closed ground to the'low resistance winding of relay 141 in kshunt of its high yresistance Winding, the current'through yrelay 104 was so reduced that kthat relay released, removing battery from thewinding of f lrelay 136. Relay 136 releases,in turn releas` ing relay 116. 'The release of relay 116 opens the energizing circuit of relay 138'but relay 138 remains operated over itsinner left contact, 4upper left contactof cam'119, to ground. Whenfthe sender ycompletes the selection of the 'called line, the sender sequence switch `advances out of position 16. *As soon asthe sequence switch'leaves position161/2, the locking circuitoffrelay 138 is opened,.and that relay releases, disconnecting'the control apparatusfrom the interoflice trunk. fIt alsoiopens the circuit of relay 145 so that relay 134 now operates from ground at the right front contact of relay 141. Theoperation of relay 134 vextends the tipr and-ring conductors 'of the trunk 162 toterminals 109 and 108 and thence over ythe back 'contacts of relay 104 to the tip and ring of ack 103 and the calling subscribers line; `The called*lineissignalledin'the usual manner andthe response of the ,subseriber` extinguishes the supervisory signal in the operators cord circuit; Vith relay 145 released, the sender relays are allreleased and the sender-'sequence switch is; advanced to position 1 where it is ready to serve another l 120 fcall. f *i 'i f F 2 is a skeleton ofthe circuit arrange# ment ofjFig. y1,; Corresponding units rbear numbers'inthe second hundred corresponding i 5 .f

to the' numbers in the` irst hundred :used in;

claimed is :y

What is 1.k Iny a telephone system,r a manual'oiiice, a-

machine switching office, ytrunks lconnecting said oices,l an Foperator7s rposition at' said zero manual oiiice equipped with cord/circuits and with acks individual to said machine switching office, selection control equipment, means responsive to the connection of a cord circuit to one of said jacks to associate said control equipment with an idle one oi' sai-d trunks, and means for thereupon associating said trunk with said jack.

2. In a telephone system, a manual oliice, a macnine switching cnice, trunks connecting said olitlces, an operators position at said manual ofice equipped with-cord ycircuits and with jacks individual to said machine switching cnice, selection control equipment, means responsive to the connection of a cord circuit to one of said jacks to associate said ycontrol equipment with an'idle one rof said trunks, and means responsive to the association of said control equipment with said i-dlertrunk for associating said trunk with said jack.

3. In a telephone system, a first office, a second oiice, trunks extending between said ofice's, a set of terminals at said firstloiifice individual to said second o'lice, selection control equipment, a 'calling line, means for eX- tending said calling line to said terminals, means responsive to the extension of said calling line to said terminals to cau-se the associationv of said control equipment with an idle one of said trunks, means for thereupon associating said trunk with said terminals, and means responsive to said control equipment to complete the connection over said trunk.

4. In a telephone system, a {inst-office, ase-c- Vond kcnice, trunks extending between -said offices, a set of terminals at said Atiret cnice in` dividual to said second oigce, selection control equipment, va calling line, means for extending said calling line to said terminals, means responsive to the extension of said calling line to said `Jterminal-s to cause the association of said control equipment with an idle vone of said trunks,.means responsive to the association of said control equipment with said idle trunk for associating said tr-unk with said terminals, and means responsive to said control equipment to complete the connection over said trunk. A

5'. In a telephone system, a first oliice, a second oiiice, a plurality of trunks extending between said oiiices, a plurality of sets of terminals `at'sai'd rst office individual to said second oliice, a plurality oi selection control ydevices, 'a calling line, means 'for extending said calling` line to one of said sets 'ot terminals, means responsive to the eXtension'ot Asaid calling linerto said terminals torcause all idle ones oft' said controld'evices to hunt for an idle lone ofsaid trunks, means responsive Vto the association of one of said control devices with an idle trunkvto arrest the hunting oper- 4ation otlthe .other control -devices and to betwen said o'ices, a switch individual to .1

each trunk, a plurality of sets of terminals et said first otiiceindividual to said Second cinco, a plurality of selection control devices, Va switch individual to each control device,

a calling line, means lfor extending said calling line to one Vof said sets of terminals, means responsive to the extension of said calling line to said terminals to cause the switch individual to each idle control devi'ceV to hunt for an idle trunk, means responsive to the association of one of said control devices with an idle trunk to stopV all of saidv switches and to cause the'switch individual tc the associated trunk to hunt for said terminals, and means eiiective following the association of said trunk with said terminals to complete the extension of the connection from said calling line under the control of said device.

7.`In a telephone system, a plurality or' trunks, each terminating ina switch, a selection control device including registers, an operator-s position equipped 'with a key set, a plurality of jackseach appearingin'a set of terminals at said switches and a cord circuit,

means responsive to the connection of said cord circuit with one of said jacks to ycause said selection control device to associate itselffwith one of said trunks, means thereupon effective to cause said trunk to associate itself with said jack, means' also responsive to the connection of said cord 'circuit with said vjack to associate said keyl set with the terminals of said jack whereby the association of said tru-nk with said jack completes the connection of said key set with said registers, and means operative following the actuationy of .said registers vto disconnect said key set from ysaid terminals.

l8. In a telephone system, a plurality of trunks each terminating kin aswitch, a selec- Ation controldevice including registers, an operators position equipped with a key set, a plurality of jacks each appearing in a set of terminals at said switch and a cord circuit,

a relay operative upon the'connection of said cord circuit with one of said acks to connect said key set with the terminals of said jack, means controlled by saidY relayto cause `said selection control device to associate itself with one of saidtrunks, means' thereupon effective to causefsaidtrunk (to-associate itself with said jack, means Aresponsive toy the' association of said trunk with said jack to complete the connection of said key set with safid registers, and

Vmeans operative following 'the actuation ci Ysaidregisters, to release said relay ,to disconnect said key `set lfrom said terminals.

9. In a telephone'systeim (aplurality of ktrunks' each terminating in aswitch',a selecof terminalsat saidswitch and a cord circuit,y a relayxoperative uponrthe connection of said cord circuit with one of said jacks to connect said key set with the terminals of said jack, means controlled by said relay to cause said selection control device toy associate itself with one ol said trunks, means thereupon effective to cause said trunk to associate itself with said jack, means responsive to the association of said trunk with said jack to complete the connection of saidkey set with said registers, and means operative following the actuation of said registers to close a low resistance shunt around said relay to release said relay and to disconnect said key set from said terminals.

l0. In a telephone system, a plurality of trunks each terminating in a switch, a ycalling line, a selection control device including registers, an operators position equipped with a key set, a plurality of acks each appearing in a set of terminals at said switches and a cord circuit for extending said calling line to one of said jacks, a relay operative upon the insertion of the plug of said cord circuit in said jack to cause the connection of said key set with the terminals of said jack and to cause the associationof said selection control device with one of said trunk circuits, means thereupon effective to cause said trunk circuit to associate itself with the terminals of said jack, means responsive to the associa.-

the actuation of said registers under the con-y trol of said key set to release said relay to disconnect said keyy set from said terminals and to extend said calling line to said trunk circuit.

11. In a telephone system, a plurality of trunks each terminating. in a switch, ka calling line, a selection control device including registers, an operators position equipped with a key set, a plurality of jacks each appearing in a set of terminals at said switches and a cord cirouitfor extending said calling line to one of said jacks, a relay operative upon the insertionof theplug of said cord circuit in said jack to cause the connection of said key set with the terminals of said jack and to cause the association of said selection control device with one of said trunk circuits, means thereupon effective to cause said trunk circuit to associate itself with the terminals of said ack, means responsive to the association of said trunk with said jack terminals to complete the connection of said key set with said registers, and means operative following the actuation of said registers under the ,control of said key set to close a low resistance shunt around said relay to release said relay,

disconnectsaid key'set from said terminals,v

andextend said calling line to said trunk cir-k'y i vice with saidtrunk ifboth ends of said trunky y arefidler- In .a telephone system, trunk circuit,

means forlmarkingeach end of saidtrunkas busy kor y"idle, an electro-responsive device, means in said device. for successively testing each endxof said trunk, andmeans for associati'nd said device'. with `saidtrunkgif bothy y ends rdfsaid trunk are idle."` :f

1,14. In a telephone system, a trunk circuit,

means for marking each end of said trunk asy f` busy or idle, an electro-responsive device, meansin said .device for testing the first end of said trunk, means effective if saidirst end isidle `to testfthe second end of saidtrunk,

andlmeans eective if said second end is also idle to associate said devicey withsaid trunk.

f 15.` In" a' telephonesystem, a plurality of trunkcircuits, means'for marking each endy ofsaid trunkas busy or idle,van electrosre-` e sponsive device, a 'switch individualto said devicefor connectingy saidy device with said trunks, means to operatey saidswitcli, means; to bring said switcli'to rest when a trunk isy encountered one end of which: is idle, means forthereupon testing the condition ofthe'y other` end'of saidtrunk, and means efectiveif advancef to the: next which is'y idle.y fr ,n V16. In a telephone .trunk thek first end of device for connecting saiddevice with said trunks, an operating magnet for said switch," g

means. for: establishing an *operating circuit forlsaid magnetmeans toopen said circuit. when atrunk is engaged one end of which `is i idle, means for-thereupon testing the condi` tion ofthe other end of said trunk, and means f effective if said other end is busy to establishalsecondcircuityfor said magnet to advance n said switchfto the next trunk one end of which isidle; f

15K-Ina telephone systempaffirst ollice, akk seoondoflicaatrunk" extending "between said i oliccfs vterminatingfatsaid first `office in a switch,lmeans atl each end of said trunk for f f marking said trunk Lbusy or idle, a plurality of sets offtermnals -forsaid switch, la calling line,means for extending said calling line to one' ,of said sets x of terminals, an electrofrespons'ivedevice, means insaid device forr testing each end ofsaid trunk, andfmeans controlledby ,said device tQaCtuatesaid switch if 13ol l f y 10o( saidlotherend'is busy to cause said switch to said trunk isfidle at both ends to extend said to complete the association of said devicey with calling line to said second office.V Y, Y said trunk.

18. In a telephone system, a firstv oice, a In witness whereof, I hereunto subscribe second office, trunks extending between said my name this day of April, A..v D., 192?, l oificesreach terminating in a switch at said f GERALD DEAKIN. first oiiice, means at each office for marking said trunks busy or idle, a plurality ofsets of terminals for said trunk switches, an electro.- responsive device, a switch individual to each device, a calling line, means for connect-4 75 10' ing said calling line to one of said sets of terminals, means to operate the switch individual to said device, means to bring said switch to rest on Va trunk one end of which is idle, means to thereupon test the Vother end of Y 80 said trunk, and meanseii'ective if the other end of said trunk is busy to advance said switch to. the next trunk one end of which is idle; 19. In a telephone system, a first oilice, a. Y 85 second oice, trunks extendingbetween said oiiices, means at Vsaid second oiiicef'or marking the distant end of said trunks as busy or idle, a plurality of jacks yat said tir-st oiiice individual to. said second office,- a plurality of v 90 electro-.responsive devices, a switch individual to each device, an operating magnet for each switch, a calling line, a cord circuit for extending said calling line to lone of said iacks, means responsive to the insertion of a 95 plug of said cord circuit in said jack to mark the inner end ci all idle trunks and to establish start circuits for they operating magnets of all idledevices, means to Vopen the start Y Y Y circuit of a magnet when the switch con@ Y me trelled therebyv engages aV trunk, theinner end of which has been marked idle, means to thereupon test the distant end of said trunk, means effective if the distant end of said n trunk is busy to establish a second circuit for Y m5 said magnet to advance said switch to the next trunk the inner end of which has been marked idle. Y i

20. In a telephone system, a first oiiice, a `njsecond oiiice, trunks extending between said iii:l

oiiices, means at said second office for mar-king the distant end of said trunks as busy or idle, a plurality of jacks at said first oiiice individual to said second oliice, a plurality 0f S electro-responsive devices, a switch individual to each device, an operating magnet for each switch, a calling line, a cord circuit for extending said calling line to one of said jacks, `means responsive to the .insertion of ay plug 120 "of said cord circuit in said ljack to mark the inner end of all idle trunks and to establish start circuits for the operating magnets of all idle devices, means to open the start circuit Y jof a magnet when the switch controlled there- 125 Y by engages a trunk, one end of which has been marked idle, means to thereupon test Vthe distant end of said trunk, means effective if the distant end of said trunk is idle to open the A65, start Vcircuits of the other control devices and 

